In Firefox with CHTML rendering, issues with speech and accessibility explorer

[Alex Jordan]

With Chrome, I go to this page:

https://pretextbook.org/examples/sample-book/noparts/html/section-note-on-proofs.html

which is a PreTeXt sample page. It is using MathJax 3.

I access the MJ menu, confirm CHTML rendering, Activate Accessibility, and reload the page. With focus on the first piece of display math (the quadratic formula), I use shift+space, and I have entered the explorer. This is all good and as I have expected.

Now I repeat this again with Firefox 147.0.2 using Mac OS Tahoe 26.2. (Worth noting that the OS is a recent upgrade and it seems to me that some issues started happening for me with this upgrade.) When I get to focus on the display math, shift+space does not enter the explorer. It exhibits the default browser behavior for shift+space, which is to scroll up some.

A strange thing is that in the MJ menu, none of the speech rules are selected. If I select any, the selection does not stick:

This is true with the inline math expressions as well (no speech rules selected), although with the inline math, I do not have the issue with the shift+space behavior.

If I switch to SVG rendering, I do not have the shift+space issue nor the speech rule selection issue.

FWIW, I feel like this behavior is new, and possibly related to my OS upgrade or a recent Firefox upgrade. This all seemed a bit much to report on GitHub, so I thought I'd start here to see if this is known. And if version 3 is even maintained at this point.